<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<#assign username="张三"/>
${username}
<hr/>

${user.userName}
<hr/>

${(user.userName)!"无名"}
<hr/>

${user.birthday?string('yyyy:MM:dd HH:mm:ss')}
<hr/>
<#if user.userName??>
    不为空
<#else >
    为空
</#if>

<hr/>

<#assign userList=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'] />

<#if (userList?size = 0)>
    数组为空
<#else >
    不为空
</#if>

<hr/>

<#list userss as u>
    ${u_index+1} ,${u.userName} <br/>
</#list>

<hr/>

${Session["user"].userName}


</body>
</html>